#include<stdio.h>
struct student{
    int x;
    char c;
} a;
void f(struct student *b);

int main()
{
    a.x=3;
    a.c='a';
    f(&a);
    printf("%d,%c\n",a.x,a.c);
}
void f(struct student *b){
    b->x=20;
    b->c='y';
}
